题干
—What did you say to Lily just now? She looked so happy.
—I praised her new hair style, saying, "______."
A：you look younger and more beautiful
B：she is more beautiful and younger
C：you looked more beautiful and younger
D：she was more beautiful and younger
答案(点此获取答案解析）
A
3C+4D的反应中，下列用不同物质的变化表示该反应的速率最快的是